In recent years, IT has been fundamental to business and taken on a growing importance. Thus, the effect of a system down is enormous. In the case of finance industry, for example, it is reported that the loss due to the system down reaches several million dollars by hour. In such an environment, a disaster recovery (hereinafter referred to as DR) to backup data to a remote site in order to continue the business even if any disaster occurs has come under the spotlight.
As a technology for realizing the disaster recovery, the technology is known, in which data update history information (primary log) of a storage device mounted in a primary site is copied to a storage device mounted in a remote site (hereinafter, this copy is referred to as “remote copy”), and the data of the primary site is recovered to the storage device of the remote site based on the copied log (secondary log) (Hereinafter, this technology is referred to as “DR system using Log synchronous transmission method”). In this DR system using Log synchronous transmission method, when the update of the primary log of the primary site, after the update of the secondary log is confirmed, the system processing of the primary site is performed (this is referred to as synchronous transmission). Therefore, it is possible to acquire the backup data with no data loss.
The technology for the remote copy between the storage devices of the primary site and the remote site is described in a catalog of “Hitachi integrated storage solution “Storeplaza””. This is the technology, in which the storages of a plurality of systems are connected through the fiber channel, and when a disk drive of one storage device is updated, this data update is reflected on the disk drives of the other storage devices.